This invention relates to an apparatus for the deposition of a uniform layer of fibres on a foraminous forming surface. More particularly the invention relates to an apparatus for continuously producing a web of randomly disposed fibres or agglomerates of fibres on a wire.
In a prior art machine a fibrous material, such as fibre pulp is delivered to a hammer mill comprising a lower curved perforated wall partially encircling the space within which the hammers are rotating. The hammer mill is located above an endless forming wire passing above a suction box.
A fibrous material is introduced into the hammer mill and is disintegrated therein so as to form loose fibres which after passage through the perforated wall flow towards the wire under the influence of the vacuum created in the suction box. These fibres are deposited on the wire so as to form a fibre layer which is then further treated, i.e. by introducing therein a binder which subsequently is cured.
In another prior art machine a stream of air containing suspended fibres is introduced into a fibre distributor comprising a housing having a perforated plane-surfaced bottom wall and a stirrer having impellers rotating a short distance above and in non-contacting relationship with the upper surface of said perforated bottom wall.
Said bottom wall is preferably mounted shortly above a wire and on the opposite side of said wire a suction box is mounted. During the rotation of the impellers the fibres introduced into said housing are distributed over said wire so as to form a fibre layer thereon, and said fibre layer is then further treated as mentioned above.
The object of the invention is to provide an improved apparatus for producing fibrous sheets or webs of uniform thickness and consistency.
A second object is to provide an apparatus comprising a fibre distributor having an improved capacity.
A further object is to provide an apparatus which can be used in connection with a suction box of reduced capacity.
A still further object is to provide an apparatus permitting an easily controllable recycling of fibre lumps from the distributor to the disintegrator.